Abstract

The behavior of phosphorus donors in bulk single-crystal monoisotopic Si_1 – xGe_x alloys (x = 0.0039–0.05) enriched by zero-spin isotopes ²⁸Si (99.998%) and ⁷²Ge (99.984%) by the electron-spin-resonance method is investigated. The hyperfine structure of the donor-electron spectrum giving information on the density of the donor wave function in the ground state on the ³¹P nucleus (I = 1/2) as well as the temperature dependences of the spin-relaxation rate (T = 3.5–30 K), which make it possible to analyze the longitudinal component T₁ relaxation mechanism and magnitude of the valley–orbit splitting of the donor state, are investigated. Interest in these investigations is also caused by the fact that the Si_1 – xGe_x alloy enriched by zero-spin isotopes (²⁸Si^isoGe, iso = 70, 72, 74, 76) is a poorly known material when compared with ²⁸Si. The irregular arrangement of germanium atoms in the lattice of the SiGe solid solution and local distortions formed by it can level isotopic effects under isotopic enrichment. However, despite broadening of the lines of the electron-spin resonance of donor electrons due to random deformations formed by dissolved germanium atoms in silicon, narrower lines of the spectra of the electron-spin resonance are observed in isotopically pure Si_1 – xGe_x single crystals at x = 0.39, 1.2, 2.9 at % when compared with similar crystals with the natural composition of silicon and germanium isotopes.

中文翻译：

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块状单晶单晶28 Si 1 – x 72 Ge x合金中磷供体的行为

摘要

零自旋同位素富集的²⁸ Si（99.998％）和⁷² Ge（99.984％）的电子自旋-富集的块体单晶Si _{1-  x} Ge _x（x = 0.0039-0.05）磷供体的行为共振法进行了研究。供体电子光谱的超精细结构，给出了³¹ P核（I = 1/2）上基态的供体波函数密度以及自旋弛豫速率的温度依赖性（T = 3.5–30 K），从而可以分析纵向分量T ₁研究了供体态的弛豫机理和谷-轨分裂的幅度。对这些研究的兴趣还归因于以下事实：零自旋同位素（²⁸ Si ^iso Ge，iso = 70、72、74、76）富集的Si _{1 –  x} Ge _x合金与²⁸硅。锗原子在SiGe固溶体晶格中的不规则排列以及由其形成的局部畸变可以在同位素富集下平整同位素效应。然而，尽管由于溶解的锗原子在硅中形成的随机变形而使施主电子的电子自旋共振线变宽，但是在同位素纯Si _{1 –  x} Ge _x中观察到了电子自旋共振谱的较窄线。与具有硅和锗同位素自然组成的类似晶体相比，x = 0.39、1.2、2.9 at％的单晶体。